The invention relates to coin validation and coin handling equipment of the kind used in pay machines, such as gaming machines, vending machines, and the like.
Various slot machines, electronic poker games, electronic roulette games, and other "coin operated" machines typically include an apparatus for analyzing inserted coins to determine whether they are of the proper value, whether they are authentic, or whether they are acceptable tokens. Would-be cheats frequently attempt to obtain free plays, etc., by inserting slugs or unauthentic coins (such as foreign coins or coins of lesser value). Another approach used by would-be cheats is to attach a string to a coin and lower it into the coin receiving mechanism to actuate a sensor that initiates operation of the machine and then rapidly withdraw the coin back through the sensor to obtain yet another coin "credit" by such use of the string. This practice is commonly known as "stringing."
A variety of mechanical and electronic coin detection/validation apparatus are known in the art. Unfortunately, none of them are adequate to meet the present needs of casino operators in Nevada to eliminate or nearly eliminate cheating. As an example of a particularly troublesome problem that no presently available coin validation system has been able to solve numerous machines in Las Vegas accept "dollar tokens". Most of the casinos obtain supplies of dollar tokens which they then sell to patrons. The patrons then go from casino to casino, and insert tokens that they purchased in one casino in coin operated machines of another casino. The uniformity of the tokens obtained from different sources is less than perfect. Often, the coin sensing circuitry of a particular gaming machine will accept valid dollar tokens from one source but not another. This makes it necessary to "broaden" the tuning of the coin sensing circuitry so that it can accept all of the dollar tokens that are likely to be inserted into it. Unfortunately, the broadening of the tuning, which effectively reduces the sensitivity of the coin detection circuitry, causes the machines to accept counterfeit slugs.
Various "coin handling" apparatus that guide or deflect inserted coins into one coin path under certain conditions (for example, for a particular coin size and/or weight) otherwise and into another path, are known in the art. However, such coin handling machines have various shortcomings. Some of them are unduly expensive. Others are not easily interfaced or used in conjunction with state-of-the-art coin validation circuitry. Commonly owned U.S. Pat. No. 4,441,602 (Ostroski et al.), incorporated herein by reference, discloses a state-of-the art coin validation circuit that includes first and second drive coils on a first printed circuit board on one side of a coin chute and driven by sinusoidal signals produced by an oscillator. First and second sense coils are disposed on a second printed circuit board on the opposite side of the coin chute and opposite to the first and second drive coils. A "reference coin" is disposed between the first sense coil and the first drive coil. An inserted coin passes through the coin chute between the second drive coil and the second sense coil, and a comparator compares the voltages induced the reference coin and then inserted in the first and second sense coils, respectively. If the induced voltages of the first and second sense coils match during the movement of the inserted coin, a valid coin signal is produced. U.S. Pat. No. 4,106,610 discloses the concept of sensing the presence of a coin moving down a chute by means of a coin presence sensor to determine if the inserted coin is a valid coin and generates a control signal that actuates a solenoid that then actuates a coin-deflecting gate that determines which of two paths the inserted coin will take. U.S. Pat. No. 3,998,309 discloses a coin-accepting device with coin position detectors and a counting circuit that cooperate to sense the sequence wherein the inserted coin passes the position detectors to determine the direction and velocity of movement of the inserted coin, and thereby detect whether "stringing" of the inserted coin is being practiced. U.S. Pat. No. 4,267,916 discloses use of optical detectors variously placed in the coin path to aid in detecting the sizes of the inserted coins. Other patents indicative of the state of the art include U.S. Pat. Nos. 3,285,382; 4,437,558; 4,243,133; and 4,298,116, the latter two being directed to anti-stringing devices. U.S. Pat. No. 4,267,916 discloses an array of optical sensors in the coin path of a coin identification system for determining the sizes, and hence the denominations of tokens, coins, etc.
Despite the availability of a variety of electronic coin validation devices that attempt to thwart would-be cheats, and despite the high market demand for sufficiently improved devices, casino operators and the like nevertheless suffer very large losses due to the inadequacy of presently available coin validation systems, because of the above difficulties in detecting well-made counterfeit tokens and slugs, also because of the difficulty of apprehending such cheats, and also because of the difficulties of successfully bringing legal action them. The difficulties of successfully bringing such legal action against cheats are due partly to the difficulty of obtaining acceptable evidence, such as photographs of the cheats triggered by the cheating activity, failure to obtain the inserted slugs and associate them with the apprehended cheat, etc. There remains an unmet need for an economical coin validation device, especially one that can distinguish both dollar tokens and silver dollar coins from slugs, and a coin handling mechanism that is economical, trouble-free, and compatible with a high-band width coin validation circuit of the type described in commonly owned U.S. Pat. No. 4,441,602.